渤海海域渤东地区烃源特征及资源潜力

CHARACTERISTICS OF HYDROCARBON SOURCE ROCKS AND RESOURCE POTENTIAL IN THE BODONG REGION OF BOHAI SEA BASIN

为了客观评价渤东地区的油气资源潜力,利用钻井和地震资料,在地层、构造和沉积研究基础上,结合岩样与油样的有机地化分析,对该区烃源岩特征、油气来源、优质烃源岩分布、烃源岩热演化特征进行了系统分析,并在此基础上用盆地模拟法对该区资源潜力进行了预测。研究认为,渤东地区发育4套烃源岩,其中沙三段和沙一段烃源岩达到优质级别,沙四段和东三段烃源岩为中等-好级别;渤东地区已发现原油来源具有多样性,但总体上以沙三段来源原油为主;在渤东地区4套烃源岩中,沙三段优质烃源岩分布广、厚度大、热演化程度高,生烃潜力占总生烃量的74.8%,是该区主力烃源岩;在该区的4个洼陷中,渤东西洼生烃强度最大,庙西北洼其次,这2个洼陷是潜在富烃洼陷。

In order to make an objective evaluation of the hydrocarbon resource potential in the Bodong Sag based on stratigraphy, tectonics and sedimentology, as well as organic geochemitry of rock and oil samples, the authors systematically studied the characteristics of source rocks, oil and gas sources, distribution of high-quality source rocks and thermal evolution of source rocks in the sag. And the resource potential of this sag is assessed using basin simulation technology. The research shows that four sets of source rocks are well developed in the sag, and the source rocks of E2S3 and E2Saare the best and the E2S4 and E3d3 fall within the middle-good level. Crude oil found in the sag can be divided into four source types and each type is distributed in definite area. Among the four types, oil from E2 Sa dominates. Among the 4 sub-sags in the Bodong Sag, west Bodong sub-sag and the north Miaoxi sub-sag are the two top potential hydrocarbon-rich sub-sags, which have more sets of high quality hydrocarbon source rocks and larger hydrocarbon generation potential.